An illuminated reticle is known from EP 0886163 B1. The reticle is a glass plate and has a marking in the form of an optical grating which is illuminated by light entering the reticle from the side. The grating parameters are selected such that the light is deflected by the marking toward the eye of the viewer.
WO 2011/113547 A1 describes a device for illuminating the marking of a reticle. The light of a divergently emitting light source is collected by a collimator lens and then enters through an entrance face into an input coupling prism cemented laterally to the reticle. The light is redirected by a reflecting face of the prism toward the peripheral edge of the reticle, where it finally impinges on the marking to be illuminated. However, this illumination device is relatively complex in construction because the light source, the collimator lens and the input coupling prism must be adjusted with respect to each other.